Boxing is a confusing sport these days, what with 17 different belts in each category, a tangle of promoters and pay-per-view deals meaning mountains have to be moved to match certain boxers, even if they're the two best in their class.

Yet boxing has hung onto its status as a 'noble' form of fighting, probably because of the contrast with the form of brawling us Brits have more direct experience of: drunk men wrestling in the street. Compared to that, boxing is indeed the sport of kings.

So to Gameloft's new mobile game, which, like several of its recent releases, is seemingly designed to go head-to-head with an EA Mobile title – in this case, Fight Night Round 3. The goal here? To become the champion of the world, obviously, knocking out anyone who stands in your way.

The game is a kind of 2D/3D hybrid, in that the characters are 2D, but they move around each other in a pseudo-3D environment. It's hard to explain, but looks good (although not quite as purdy as Fight Night Round 3).

Control-wise, '5' jabs, '1' and '3' punch left and right hooks to the head, while '7' and '9' trigger left and right hooks to the body. Holding down a button winds up a more powerful punch, although you're vulnerable while doing it.

If it sounds complicated, well, it is, but as long as you're in a position to play two-handed, you'll soon master the controls and be dodging, weaving and punching like a pro.

Once you do you'll be able to notice some great little effects, such as blood spattering the screen when you land a particularly good uppercut, or the flashing slo-mo knockdown sequence.

You can play an Exhibition match, but really, it's all about the Career mode, which sees you first choosing Rookie, Amateur or Pro difficulty level, and then embarking on your quest to be the best. This journey includes a trip through a decent character-customiser to tweak your pugilist, before launching you into a calendar-based interface. It's not just about fighting, though – you have to train to improve your skills, and also rest to recover your energy.

The training takes the form of three mini-games: Punching Mitts, Heavy Bag, and Speed Bag, which affect your power, endurance and strength to varying degrees. They're all based on the game's core engine, although Speed Bag throws in some rhythm-action to break things up.

The Career mode provides plenty of depth, kicking off with warm-up fights, before getting you challenging for a series of championships as you work your way up the rankings. It certainly held us gripped, as did the steadily increasing difficulty as we faced better boxers.

Want more involvement? You can have it. As you progress through Career, you unlock other game modes: Universal Championship, Gym Challenge, Technical Proficiency, and Time Attack Challenge.

And all the while, the game is tracking your progress via an Achievements section, which gives you awards for reaching certain goals – from winning 20, 40 or 60 bouts, through to more esoteric stuff like winning a fight using just low shots, or defeating someone in less than 30 seconds.

There's a lot to KO Legends, in other words. And thankfully, backing the substance is a class act, offering accessible boxing action with an engrossing career mode wrapped around it. Outstanding stuff.